JP2002234135A - Printing machine dryer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always operate an exhaust fan in an optimum operation condition from economical and work-environmental aspects with regard to a printing machine dryer system. SOLUTION: The system has a dryer 1 for drying a print 3 by hot air, the exhaust fan 4 for sucking/discharging ink components evaporated from the print 3 into the dryer 1 by the drying, a pressure detector 12 for detecting the pressure of the dryer 1, and a controller 13 for controlling the rotation of the fan 4 based on the output from the detector 12 so that the dryer 1 has a prescribed negative pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dryer system provided in a commercial offset printing press.

[0002]

2. Description of the Related Art As an example of a dryer system (flow) of a commercial offset printing machine, there is a so-called direct combustion system in which a solvent in ink is directly burned to be treated. FIG.
FIG. 1 is a schematic configuration diagram showing a conventional direct combustion type dryer system. As shown in FIG. 2, a nozzle unit 2 is provided in the dryer 1, and the hot air for drying supplied from the nozzle unit 2 evaporates and dries the ink of the printing paper 3 traveling in the dryer 1. The solvent in the ink evaporated from the printing paper 3 is sucked by the exhaust fan 4 and sent to the deodorizing device 5, where the solvent in the ink is directly burned by the deodorizing burner 6 in the deodorizing device 5.

At this time, since the solvent in the ink generates a large amount of combustion heat in the deodorizing device 5, the exhaust gas still maintains a high temperature even after leaving the high-temperature heat exchanger 7. In order to effectively use this high-temperature energy, the high-temperature heat exchanger 7
In the low-temperature heat exchanger 8 downstream of the heat exchanger, heat is recovered to generate hot air for drying, and the hot air is circulated to the circulation fans 9 and 10.
To supply the printing paper 3 from the nozzle unit 2.

The circulation fan 9 circulates and supplies hot air for drying, as indicated by an arrow in FIG.
The hot air supplied from the nozzle 2 has a normal temperature of 160 to 20.
Although the temperature is 0 ° C., the heat recovered from the low-temperature heat exchanger 8 is usually used as the heat source. If the recovered heat is insufficient, the combustion heat generated by burning the burner 11 is also used. The hot air supplied from the nozzle 2 is sucked again by the circulation fan 9, and is supplied again from the nozzle 2 by receiving heat from the low-temperature heat exchanger 8 or receiving heat from the burner 11. Such a circulation cycle of hot air is called a circulation fan.

As shown in FIG. 2, the circulation fan 10 sucks the hot air supplied from the nozzle again and supplies it again from the nozzle 2. As shown by the dashed line in FIG. 2, a duct is provided in the supply line for the circulation fan 9 and the circulation fan 10 so as to partially bypass and branch, so that heat is also supplied to the circulation fan 10 side. ing. Further, the burner 11 operates only when the combustion heat of the solvent cannot be sufficiently recovered at the start of the present system. Normally, only the pilot burner ignites and stands by.

[0006]

By the way, in the above-mentioned dryer system, the pressure inside the dryer 1 is usually large so that the evaporated solvent does not leak from the entrance of the printing paper of the dryer 1. It is adjusted by suction of the exhaust fan 4 so that the pressure becomes negative with respect to the atmospheric pressure. That is, when the suction capacity of the exhaust fan 4 is increased, the negative pressure in the dryer 1 is increased, and leakage of the evaporated solvent to the outside can be suppressed.

However, as the suction flow rate of the exhaust fan 4 increases, the load on the deodorizing burner 6 increases. Therefore, if the suction capacity of the exhaust fan 4 is increased, the fuel consumption increases and the economic efficiency deteriorates. That is, suppressing the leakage of the solvent to the outside and improving the fuel efficiency are contradictory, and the optimal suction that can suppress the leakage of the solvent to the outside while suppressing the decrease in the fuel consumption. It is necessary to control the operation of the exhaust fan 4 so as to obtain the flow rate.

Although the suction capacity of the exhaust fan 4 depends on the number of revolutions of the fan, the exhaust fan 4 is normally operated under inverter control, and the frequency of the exhaust fan 4 is changed. The fan rotation speed can be changed to adjust the exhaust flow rate (suction capacity). At present, the operator changes the frequency (the number of revolutions) of the exhaust fan 4 while checking the operation state of the dryer system each time.

In order to achieve both suppression of solvent leakage to the outside and reduction of fuel consumption, it is effective to always maintain the pressure in the dryer 1 at a predetermined level. That is, it is effective to adjust the fan rotation speed (i.e., suction capacity) of the exhaust fan 4 according to the negative pressure state in the dryer 1. The negative pressure in the dryer 1 fluctuates every moment depending on the amount of air brought in from the outside due to a change in operating speed and the amount of evaporated solvent depending on the amount of ink applied.

However, the current adjustment of the rotational speed of the exhaust fan 4 is not performed based on the state of the negative pressure in the dryer 1 or a parameter that affects the negative pressure in the dryer 1. Although it depends on the driving situation, it relies on the intuition of the worker, which incurs a burden on the worker and is a difficult method to always operate the exhaust fan 4 at the optimum rotation speed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a printing machine dryer system capable of operating an exhaust fan in an optimal operating state at all times, both economically and in a workplace environment. The purpose is to provide.

[0012]

SUMMARY OF THE INVENTION Accordingly, a printing press dryer system according to the present invention is a dryer system provided for a printing press, comprising: a dryer for drying printed matter with hot air;
An exhaust fan for sucking and discharging the ink component evaporated from the printed matter by the hot air drying from the dryer, a pressure detecting device for detecting a pressure in the dryer, and a predetermined inside of the dryer based on an output from the pressure detecting device. And a control device for controlling the rotation of the exhaust fan so as to achieve the negative pressure state.

The control device includes a conversion device for converting an output from the pressure detection device into a voltage output or a current output, and a voltage output or a current output converted by the conversion device and an optimum output in the dryer. An arithmetic circuit for calculating a difference between a voltage output or a current output corresponding to a negative pressure, and a control circuit for controlling a rotation speed of the exhaust fan based on the difference calculated by the arithmetic circuit are provided. Is preferred.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a printing press dryer system as an embodiment of the present invention. In FIG. 1, the same reference numerals as those in FIG. 2 denote the same components. As shown in FIG. 1, the dryer system of the present embodiment includes a dryer 1 provided with a nozzle unit 2 therein and an ink in the ink evaporated from a printing paper (printed material) 3 in the dryer 1 as in the related art. An exhaust fan 4 for sucking the solvent, a deodorizing device 5 for burning and deodorizing the solvent sucked by the exhaust fan 4, a high-temperature heat exchanger 7 and a low-temperature heat exchanger 8 for performing heat exchange on the combustion-treated exhaust gas. Circulating fans 9 and 10 for circulating hot air generated through the low-temperature heat exchanger 8 and a burner 11 for generating hot air.

Thus, in the dryer 1, the ink of the printing paper 3 traveling in the dryer 1 is evaporated and dried by the hot air for drying supplied from the nozzle portion 2, and the printing paper 3 evaporates. The solvent in the ink thus obtained is sucked by the exhaust fan 4 and sent to the deodorizing device 5, where the solvent in the ink is directly burned by the deodorizing burner 6 in the deodorizing device 5.

At this time, since the solvent in the ink generates a large amount of heat of combustion in the deodorizing device 5, the exhaust gas still maintains a high temperature even after leaving the high-temperature heat exchanger 7. In order to effectively use the high-temperature energy, heat is recovered in the low-temperature heat exchanger 8 downstream of the high-temperature heat exchanger 7 to generate hot air for drying, and the hot air is circulated from the nozzle unit 2 by the circulation fans 9 and 10. The printing paper 3 is supplied.

The burner 11 is activated only when the heat of combustion of the solvent cannot be sufficiently recovered at the start of the system. Normally, only the pilot burner ignites and stands by. The burners 6, 6, and 11 are supplied with fuel and combustion air to perform combustion.

The circulation route of the hot air for drying by the circulation fans 9 and 10 is not shown in FIG. 1, but is as shown by an arrow in FIG. The heat recovered from the exchanger 8 is used. If the recovered heat is insufficient, the combustion heat generated by burning the burner 11 is also used. Although not shown in FIG. 1, as shown by a broken line in FIG. 2, a duct is provided in the supply line of the circulation fan 9 and the circulation fan 10 to branch off partially.

The dryer system of the present embodiment has a digital manometer 12 as a pressure detecting device (negative pressure detecting device) for measuring the pressure (negative pressure) in the dryer 1 and a digital manometer 12 in addition to the above configuration. A control device 13 controls the rotation of the exhaust fan 4 based on the output from the manometer (pressure detection device) 12 so that the inside of the dryer 1 is brought into a predetermined negative pressure state.

The controller 13 converts a negative pressure detection output from the digital manometer 12 into a voltage output, and outputs a voltage from the converter 14 and a voltage corresponding to a preset optimal negative pressure in the dryer. An arithmetic circuit 15 for calculating a difference from the output is provided with a control circuit 16 for controlling the rotation speed of the exhaust fan 4 based on the difference calculated by the arithmetic circuit 15.

Here, a digital manometer 12 is provided as a negative pressure detecting device in the dryer. The digital manometer 12 is provided outside the dryer 1 and detects the inside of the dryer 1 through a communication pipe such as a vinyl tube 17. The pressure at the point 18 is introduced into the digital manometer 12 so that the pressure in the dryer 1 can be detected.

In this case, the position of the detection point 18 at the tip of the vinyl tube 17 may be any position as long as it is inside the dryer 1. For example, the detection point 18 is arranged near the nozzle 2 as shown in FIG. The tip of the tube 17 may be fixed with a commercially available heat-resistant tape or the like. It is sufficient that the tube diameter of the vinyl tube 17 is about 4 to 5 mm, and a commercially available material may be used as long as the material has heat resistance. That is, the specifications of the tube 17 are not limited at all.

It is preferable that the tube 17 is arranged in the dryer 1 so as not to interfere with the operation such as contact with printing paper or the like, drawn out of the system of the dryer 1 and connected to the digital manometer 12. A digital manometer can normally output a voltage. If you carry out the test here in advance, you can make a test curve of negative pressure and voltage output in the dryer,
The negative pressure in the dryer can be taken out as a voltage output.

Further, a voltage output with respect to the optimal negative pressure in the dryer and a rotation speed (frequency) of the exhaust fan 4 at that time are previously determined.
For example, when the negative pressure in the dryer 1 fluctuates due to the actual operation state, the fluctuation of the voltage output is calculated by the arithmetic circuit 15, the frequency is changed by the control circuit 16, and the predetermined optimum It is easy to change the rotation speed of the exhaust fan 4 so that the pressure becomes negative.

Since the printing press dryer system according to one embodiment of the present invention is configured as described above, the digital manometer 12 as a pressure detecting device is supplied through the vinyl tube 17 during the operation of the dryer 1. The controller 13 measures the pressure (negative pressure) in the dryer 1 (in this case, the detection point 18), and the controller 13 exhausts the inside of the dryer 1 based on the output from the digital manometer 12 so that the inside of the dryer 1 has a predetermined negative pressure. The rotation of the fan 4 is controlled.

That is, in the control device 13, the conversion device 14
Converts the negative pressure detection output from the digital manometer 12 into a voltage output, and the arithmetic circuit 15 calculates the difference between the voltage output from the converter 14 and the voltage output for the preset optimal negative pressure in the dryer. Then, the control circuit 16 controls the rotation speed of the exhaust fan 4 based on the difference calculated by the calculation circuit 15.

Therefore, the interior of the dryer 1 is always maintained at the set optimal negative pressure. For example, the operating speed is increased, and the amount of air taken into the dryer is increased. Even in the case where the pressure is not applied, the rotation speed of the exhaust fan 4 can be automatically adjusted to correspond to the output fluctuation, so that the optimal operating conditions can always be set. Become.

As a result, while the inside of the dryer 1 is kept in a negative pressure state to prevent the leakage of the solvent to the outside of the dryer 1, it is possible to prevent the inside of the dryer 1 from being in an excessively negative pressure state. As a result, the load on the deodorizing burner 6 is not excessively increased, and an increase in fuel consumption can be prevented. In this way, according to the printing press dryer system, the negative pressure in the dryer 1 can be always maintained at an optimum value, and the fuel consumption can be prevented while reliably preventing the solvent from leaking out of the dryer 1. Can be prevented, and a printing press dryer system that is excellent both economically and workplace environment can be realized.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can be variously modified without departing from the spirit of the present invention. For example, the pressure detecting device (negative pressure detecting device) is not limited to the digital manometer 12 as long as it can detect the negative pressure in the dryer. The piezoelectric element may be a general pressure sensor (for example, a semiconductor piezoresistive sensor, Shape sensor, SAW sensor, etc.).

In the above embodiment, the vinyl tube 17 and the digital manometer 12 are combined to convert the negative pressure (pressure) detection output into a voltage output to perform the calculation. The calculation may be performed by converting to a current output. Further, the control device 13 only needs to control the inside of the dryer 1 to a predetermined negative pressure state based on the detection result of the pressure detection device, and is not limited to the above embodiment.

[0031]

As described in detail above, according to the printing press dryer system of the present invention, the pressure detecting device detects the pressure in the dryer and the control device performs the operation based on the detected pressure. Since the rotation of the exhaust fan is controlled so that the inside of the dryer is at a predetermined negative pressure state, the inside of the dryer can always be initially adjusted to the predetermined negative pressure state without bothering the operator. Become. Therefore,
It is possible to achieve both suppression of solvent leakage to the outside and suppression of reduction in fuel consumption, and it is possible to operate the exhaust fan in an optimal operating state both economically and workplace environment.

According to the printing press dryer system of the present invention, in the control device, the output from the pressure detecting device is converted into the voltage output or the current output by the conversion device, and the converted value is converted by the arithmetic circuit. The difference between the voltage output or the current output and the voltage output or the current output corresponding to the preset optimal negative pressure in the dryer is calculated, and the rotation speed of the exhaust fan is controlled through the control circuit based on the calculated difference. As a result, the inside of the dryer can always be maintained at a predetermined negative pressure state.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a printing press dryer system as one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a conventional printing press dryer system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Dryer 2 Nozzle part 3 Printing paper (printed matter) 4 Exhaust fan 5 Deodorizing device 6 Deodorizing burner 7 High-temperature heat exchanger 8 Low-temperature heat exchanger 9, 10 Circulating fan 11 Burner 12 Digital as a pressure detecting device (negative pressure detecting device) Manometer 13 Control device 14 Conversion device 15 Arithmetic circuit 16 Control circuit 17 Vinyl tube 18 Detection point

Claims (2)

[Claims] 1. A dryer system provided in a printing press, comprising: a dryer for drying printed matter with hot air; an exhaust fan for sucking and discharging ink components evaporated from the printed matter into the dryer by the hot air drying; And a control device for controlling the rotation of the exhaust fan so that the inside of the dryer is brought into a predetermined negative pressure state based on the output from the pressure detection device. Characterized by a printing press dryer system. 2. The controller according to claim 1, wherein the controller converts the output from the pressure detector into a voltage output or a current output, and a voltage output or a current output converted by the conversion device and a preset value in the dryer. And a control circuit that controls the rotation speed of the exhaust fan based on the difference calculated by the calculation circuit. The printing press dryer system according to claim 1, wherein: